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General Description and Overview
GARD 8000 Distance Relay
RFL Electronics Inc.
SECTION 2.
GENERAL DESCRIPTION
AND OVERVIEW
2.1
DESCRIPTION
The GARD 8000 Distance Module incorporates all functions required for complete line protection.
Using the most advanced digital technology, based on microprocessors and DSPs, it provides distance
protection, together with current, voltage and frequency protection functions, recloser, synchronism
check, supervision functions and metering.
2.2
GENERAL OVERVIEW
The GARD 8000 Distance Module provides
•
Distance measuring elements (with their supervisory units, such as detectors for close onto
fault, remote breaker opening, loss-of-potential, power swing and load encroachment)
•
Voltage measuring elements (phase over/undervoltage and ground overvoltage)
•
Current measuring elements (instantaneous and time overcurrent, directional or non directional
phase and ground overcurrent, stub bus and thermal protection, open phase and breaker failure
detectors)
•
Frequency measuring elements (over/underfrequency and rate of change of frequency)
The distance measuring elements may be used in Pilot Protection Schemes to speed up remote-end
tripping. In addition, pilot scheme logic for the negative sequence and ground directional elements are
also available. These can use the same channel as the distance protection pilot logic, or separate
channels.
The GARD 8000 Distance Module can be configured for single pole tripping and logic for series
compensated line applications is included.
The GARD 8000 Distance Module recloser function provides up to 3 reclose attempts. The recloser
can be supervised by the built-in synchronism check function, or by the use of an external device.
Breaker monitoring functions are provided to detect an excessive number of tripping operations and
excessive breaking current.
Other GARD 8000 Distance Module features are digital fault records (oscillography), fault reports
(with fault location) and event records.
March 1, 2009
2-1
973.334.3100